Evaluation of risks for non‐Hodgkin's Lymphoma by occupation and industry exposures from a case‐control study

Abstract

The etiology of non-Hodgkin's lymphoma (NHL) is not well understood. To develop hypotheses on causes of this tumor, data from a population-based case-control interview study of 1,867 white men (622 cases and 1,245 controls) in Iowa and Minnesota conducted during 1980-1983 were examined. Subjects, or their next of kin, were interviewed to obtain information on agricultural exposures, work history, medical conditions, and family history. This analysis focuses on risks of NHL by occupation, by industry, and by selected exposures. Although many comparisons were made, few significant associations were observed. Small numbers and limitations in exposure assessment, however, would tend to reduce opportunities to detect associations. The strongest finding was with various occupations that work in metals and metal products. The analysis by exposure estimates also uncovered a significant association with metals, but risks did not increase with estimated intensity of exposure. Slightly elevated risks were also noted among persons employed as painters and construction workers, agricultural and forestry workers, printers and typesetters, funeral directors and embalmers, and dry cleaners. Although the overall risks for benzene and other solvents were small, they increased slightly with level of assigned exposure. Although some associations may be due to chance, several of these occupations and industries have been linked to lymphoma in other investigations and deserve further attention.

The non-Hodgkin lymphomas: A review of the epidemiologic literature

“…203 In a Swedish case-control study, NHL cases were significantly more likely to report exposure to ''high-grade'' organic solvents (OR 5 3.5, 95% CI: 1.7-7.1). 117 Blair et al 170 reported a significant positive association between ''higher intensity'' non-benzene solvent exposure and risk of diffuse (small cleaved cell, mixed cell and large cell) NHL (OR 5 2.4, 95% CI: 1.2-5.0), but no association with follicular or ''other'' NHL types. Tatham et al 71 reported a significant positive association between solvent exposure and risk of small cell diffuse lymphoma (OR 5 1.60, 95% CI: 1.10-2.20), but results were null for large cell diffuse lymphoma and follicular lymphoma.…”

“…191,195 Numerous studies examined the relation between solvent exposure and risk of NHL. When solvents were evaluated as a general category, most studies observed nonsignificant positive associations with NHL risk, 20,21,29,71,105,118,129,170,202 and 2 reported inverse associations. 114,142 No association between occupational exposure to organic solvents and lymphatic and hematopoietic cancer was reported in a meta-analysis of 26 studies (meta-SMR 5 1.05, 95% CI: 0.92-1.21).…”

“…Parodi et al 197 examined the relative risk of NHL in an Italian municipality with close residential proximity to a coke oven, an industrial source of environmental benzene, and reported significant positive associations among men (RR compared to controls in Cornigliano [a district in Genoa] 5 2.4, 95% CI: 1.4-4.1; RR compared to controls in Genoa 5 1.7, 95% CI: 1.2-2.6), but not women (RR with Cornigliano controls 5 1.2, 95% CI: 0.6-2.5; RR with Genoa controls 5 1.0, 95% CI: 0.6-1.7). Overall, the epidemiologic evidence does not support a causal association between benzene exposure and NHL, as individual cohort and case-control studies have been inconsistent, with relative risk estimates above 21,[31][32][33]170,194,196,198,199 and below 31,176,191,[200][201][202] 1.0, and nonsignificant findings from pooled analyses ranging between 0.90 and 1.31. 191,195 Numerous studies examined the relation between solvent exposure and risk of NHL.…”

“…226 Exposure to formaldehyde has not been shown to be associated with risk of NHL. 71,170,227 The association between nitrates in drinking water and risk of NHL has been examined in several ecologic studies, with inconsistent results. Ward et al 228 reported an odds ratio of 2.0 for NHL in association with the highest category of average nitrate exposure in Nebraska community water supplies (95% CI: 1.1-3.6), but no such association was reported in studies conducted in Iowa 229 or Minnesota.…”

“…Several studies yielded relative risk estimates close to 1.0 among persons exposed to diesel exhaust [170][171][172][173][174] or gasoline vapors, 29,175,176 and there is no epidemiologic evidence supporting a causal relationship between working in the petroleum industry and risk of developing NHL. Relative risks have been near unity in petroleum worker cohort studies in California, 177,178 Texas, [179][180][181] Louisiana, 182,183 US, [184][185][186] Canada 187,188 and Australia.…”